From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Graph plotting torsional vibration tests on a B.80 No.2 engine, comparing a B.80 damper with a Studebaker damper.
| Identifier | ExFiles\Box 124\1\ scan0228 | |
| Date | 20th July 1939 | |
| TORSIONAL VIBRATION TESTS ON B.80 NO.2 B.80 DAMPER .0485 SLUG FT² 318 LBS. FT. DEGREE⁻¹ STUDEBAKER DAMPER .0246 SLUG FT² 55 - 60 RUBBERS FIG. 7 VIBRATION AMPLITUDE DEGREES RM{William Robotham - Chief Engineer}/JRS 20-7-39 | ||